urban design criteria for earthquake preparedness in organic urban areas of tehran

there are large areas of the world where seismicity is high while they form the whole or parts of urban conglomeration. iran can be literally compared to a large shaking table; various parts of it have been stricken by earthquake in the last four decades(1). tehran is also expected to have a major earthquake in the near future(2). therefore, urban design criteria for earthquake preparedness in organic urban areas of tehran should be prepared. among various parts of the city, the organic areas are facing more problems due to their old and unsafe structures and being located in narrow lanes and alleys while gas pipes running every where. in case of earthquake, people will be traped in these places where it will be very difficult for the fire fighting vehicles, ambulances and othe facilities to reach to the affected parts to provide health care services and aid. this paper tries to point out that although prevention of earthquake or strengthening of each and every urban structure is not possible, but at the same time the harsh effect can be toned down with the preparedness of urban transport and built form along them. it is a well known fact that after every earthquake, victims are trapped alive below the debris. this makes it imperative that a hierarchy of earthquake safe centers shall be available at all levels of the settlements and a network of roads is essential for the free flow of emergency vehicles and equipment to make the job of relief and rescue work easier.